Fish are an increasingly important source of food and income; global annual consumption projected to rise from 110 million tons in 2010 to more than 200 million tons in 2030. Whereas rates of wild fish capture are flat or declining due to overfishing and loss of habitat, the global mariculture harvest is growing at a rate in excess of 8% per annum. However, the emergence of infectious diseases in aquaculture threatens production and may also impact wild fish populations. Atlantic salmon (Salmo salar L.) are amongst the most popular of farmed fish, accounting for annual production of more than 1 million tons. Atlantic salmon mariculture has been associated with epidemics of infectious diseases that threaten not only local production, but also wild fish coming into close proximity to marine pens, or fish escaping from them. Heart and skeletal muscle inflammation (HSMI) is a frequently fatal disease of farmed Atlantic salmon. First recognized in one farm in Norway in 1999 (Kongtorp et al., J Fish Dis 27, 351-358 (2004)), HSMI was subsequently implicated in outbreaks in other farms in Norway and the United Kingdom (Ferguson et al., J Fish Dis 28, 119-123 (2005)). Although pathology and disease transmission studies indicated an infectious basis, efforts to identify an agent were unsuccessful.
HSMI is transmissible but the causal agent has not been previously isolated. HSMI is an important disease that threatens aquaculture. There is a need for immunogenic compositions and vaccines suitable for preventing and containing PRV infection and for treating animals having HSMI. This invention addresses these needs.